Develop Reference

How can I handle this IndexOutOfBounds exception?

I am working on a text-based adventure game and need some help handling the IndexOutOfBounds exception on the getUserRoomChoice() function. I have an index of 3 on the menu so when the user enters a number > 3, it throws that exception. I tried using a try-catch on the line where it prompts the user to "Select a Number" but it is not catching it.
Here is my main class:
import java.util.Scanner;
public class Game {
private static Room library, throne, study, kitchen;
private static Room currentLocation;
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
initialSetupGame();
String reply;
do {
printNextRooms();
int nextRoomIndex = getUserRoomChoice();
Room nextRoom = getNextRoom(nextRoomIndex);
updateRoom(nextRoom);
System.out.print("Would you like to continue? Yes/No: ");
reply = input.nextLine().toLowerCase();
} while ('y' == reply.charAt(0));
goodbye();
}
public static void initialSetupGame() {
// Instantiate room objects of type Room
library = new Room("Library");
throne = new Room("Throne");
study = new Room("Study");
kitchen = new Room("Kitchen");
// Connect the objects to each other
library.addConnectedRoom(throne);
library.addConnectedRoom(study);
library.addConnectedRoom(kitchen);
throne.addConnectedRoom(library);
throne.addConnectedRoom(study);
throne.addConnectedRoom(kitchen);
study.addConnectedRoom(library);
study.addConnectedRoom(throne);
study.addConnectedRoom(kitchen);
kitchen.addConnectedRoom(library);
kitchen.addConnectedRoom(study);
kitchen.addConnectedRoom(throne);
// Welcome message
System.out.println("Welcome to Aether Paradise, "
+ "a game where you can explore"
+ " the the majestic hidden rooms of Aether.");
// Prompt user for a name
Scanner input = new Scanner(System.in);
System.out.print("\nBefore we begin, what is your name? ");
String playerName = input.nextLine();
System.out.print("\n" + playerName +"? Ah yes. The Grand Warden told us"
+ " to expect you. Nice to meet you, " + playerName + "."
+ "\nMy name is King, a member of the Guardian Aethelorian 12"
+ " who protect the sacred rooms of Aether."
+ "\nAs you hold the Warden's signet ring, you have permission"
+ " to enter.\n\nAre you ready to enter? ");
String response = input.nextLine().toLowerCase();
if ('n' == response.charAt(0)) {
System.out.println("Very well then. Goodbye.");
System.exit(0);
}
if ('y' == response.charAt(0)) {
System.out.println("\nA shimmering blue portal appeared! You leap "
+ "inside it and your consciousness slowly fades...");
}
else {
System.out.println("Invalid input. Please try again.");
System.exit(1);
}
// Set the player to start in the library
currentLocation = library;
System.out.print("\nYou have spawned at the library.");
System.out.println(currentLocation.getDescription());
}
public static void printNextRooms() {
// Lists room objects as menu items
System.out.println("Where would you like to go next?");
currentLocation.printListOfNamesOfConnectedRooms();
}
// How to handle the exception when input > index?
public static int getUserRoomChoice() {
Scanner input = new Scanner(System.in);
System.out.print("(Select a number): ");
int choice = input.nextInt();
return choice - 1;
}
public static Room getNextRoom(int index) {
return currentLocation.getConnectedRoom(index);
}
public static void updateRoom(Room newRoom) {
currentLocation = newRoom;
System.out.println(currentLocation.getDescription());
}
public static void goodbye() {
System.out.println("You walk back to the spawn point and jump into"
+ "the portal... \n\nThank you for exploring the hidden rooms "
+ "of Aether Paradise. Until next time.");
}
}
Room Class
import java.util.ArrayList;
public class Room {
// Instance variables
private String name;
private String description;
private ArrayList<Room> connectedRooms;
// Overloaded Constructor
public Room(String roomName) {
this.name = roomName;
this.description = "";
connectedRooms = new ArrayList<>();
}
// Overloaded Constructor
public Room(String roomName, String roomDescription) {
this.name = roomName;
this.description = roomDescription;
connectedRooms = new ArrayList<>();
}
// Get room name
public String getName() {
return name;
}
// Get room description
public String getDescription() {
return description;
}
// Add connected room to the array list
public void addConnectedRoom(Room connectedRoom) {
connectedRooms.add(connectedRoom);
}
// Get the connected room from the linked array
public Room getConnectedRoom(int index) {
if (index > connectedRooms.size()) {
try {
return connectedRooms.get(index);
} catch (Exception ex) {
System.out.println(ex.toString());
}
}
return connectedRooms.get(index);
}
// Get the number of rooms
public int getNumberOfConnectedRooms() {
return connectedRooms.size();
}
// Print the connected rooms to the console
public void printListOfNamesOfConnectedRooms() {
for(int index = 0; index < connectedRooms.size(); index++) {
Room r = connectedRooms.get(index);
String n = r.getName();
System.out.println((index + 1) + ". " + n);
}
}
}

You have to use try-catch in function call of getNextRoom().
Because getNextRoom(nextRoomIndex) is causing the exception. You have to put those two statements in try block.
Change this to
Room nextRoom = getNextRoom(nextRoomIndex);
updateRoom(nextRoom);
this
try{
Room nextRoom = getNextRoom(nextRoomIndex);
updateRoom(nextRoom);
} catch(Exception e){
System.out.println("print something");
}

You must have a closer look to the piece of code, where you try to access the list (or array). That is the part, where the exception is thrown, not when the user enters it. There you have to check, if the given index is larger than the size of your list.
if( index >= list.size()) {
// handle error / print message for user
} else {
// continue normaly
}
In your case, it would probably be in the method getConnectedRoom(int index) in class Room.

Where is your try/catch block for the specific part? anyway, you can use IndexOutOfBound or Custome Exception for it.
1.create a custom Exception Class
class RoomeNotFoundException extends RuntimeException
{
public RoomeNotFoundException(String msg)
{
super(msg);
}
}
add try/catch block for the specific part
public class Game
{
do {
printNextRooms();
int nextRoomIndex = getUserRoomChoice();
if(nextRoomeIndex>3)
{
throw new RoomNotFoundException("No Rooms Available");
}else{
Room nextRoom = getNextRoom(nextRoomIndex);
updateRoom(nextRoom);
System.out.print("Would you like to continue? Yes/No: ");
reply = input.nextLine().toLowerCase();
}
} while ('y' == reply.charAt(0));
}
Or you can use IndexOutOfBoundException instead of RoomNotFoundException

What is the correct syntax for validating user input?

My code creates a set of sport results using a scanner, the user enters input in this format "Home team : Away team : Home score : Away score" - each part is split into a string in the array. I want to create an error message if one part is missing for example "Error, Home team seems to be missing" for each corresponding section however;
I am a beginner and have been trying to put an else-if condition in the for loop to help make this error message however I am doing something wrong judging by the amount of errors I am getting (delete this token).

This code will help your program to validate the user-input as per the your requirements in your question, if any of the inputs is missed by the user it is reported to him:
import java.util.Scanner;
public class Test4 {
public static void ismissing(int i)
{
switch(i)
{
case 0:
System.out.println("Home team missing");
break;
case 1:
System.out.println("Away team missing");
break;
case 2:
System.out.println("Home score missing");
break;
case 3:
System.out.println("Away score missing");
break;
}
}
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Input as follows; ");
System.out.println("Home team : Away team : Home score : Away score");
String str=scanner.nextLine();
String array[]=str.split(":");
for(int i=0;i<array.length;i++)
{
if(array[i].equals(" "))
{
ismissing(i);
System.exit(0); //will exit program if something is missing
}
}
System.out.println("Correct Input");
}
}

If you are going to be creating numerous games, I would recommend you make a Game class as this will make it easier to manage a Game object as opposed to 2 Strings and 2 Integer values. With a Game object you can also output your desired string output using the toString method of your Game object. When getting the user input, the criteria I used is such that team names cannot be blank and team scores cannot be less than 0. If the user enters and empty string or an invalid integer, then we simply output a message indicating the invalid input and have the user try again until they get valid input. If you want to exit when this happens you could change this to accommodate a graceful exit of the program when the user enters invalid data.
I made two methods in the main, one to get a valid String team name, and another to get a valid Integer for the score. Again if the user inputs invalid data we will loop until the input is valid.
Game Class:
public class Game
{
String homeTeam = "";
String awayTeam = "";
int homeScore = -1;
int awayScore = -1;
public Game(String inHomeTeam, int inHomeScore, String inAwayTeam, int inAwayScore)
{
super();
this.homeTeam = inHomeTeam;
this.awayTeam = inAwayTeam;
this.homeScore = inHomeScore;
this.awayScore = inAwayScore;
}
#Override
public String toString()
{
return homeTeam + "[" + homeScore + "] | " + awayTeam + "[" + awayScore + "]";
}
public String getHomeTeam() {
return homeTeam;
}
public void setHomeTeam(String homeTeam) {
this.homeTeam = homeTeam;
}
public String getAwayTeam() {
return awayTeam;
}
public void setAwayTeam(String awayTeam) {
this.awayTeam = awayTeam;
}
public int getHomeScore() {
return homeScore;
}
public void setHomeScore(int homeScore) {
this.homeScore = homeScore;
}
public int getAwayScore() {
return awayScore;
}
public void setAwayScore(int awayScore) {
this.awayScore = awayScore;
}
}
Main
public class Main
{
static Scanner scanner = new Scanner(System.in);
static Game[] allGames;
static String homeTeam = "";
static String awayTeam = "";
static int homeScore = -1;
static int awayScore = -1;
static int numberOfGames = 0;
public static void main(String[] args)
{
numberOfGames = GetUserInt("How many games do you want to enter - 100 or less: ");
if (numberOfGames > 100)
numberOfGames = 100;
allGames = new Game[numberOfGames];
for (int i = 0; i < numberOfGames; i++) {
homeTeam = GetUserString("Enter the home team name: ");
homeScore = GetUserInt("Enter the home team score: ");
awayTeam = GetUserString("Enter the away team name: ");
awayScore = GetUserInt("Enter the away team score: ");
allGames[i] = new Game(homeTeam, homeScore, awayTeam, awayScore);
}
// output the users games
for(Game curGame : allGames)
{
if (curGame != null)
System.out.println(curGame.toString());
}
}
private static String GetUserString(String prompt)
{
String input = "";
while(true) {
System.out.print(prompt);
input = scanner.nextLine();
if (input.length() > 0)
return input;
else
System.out.println("Invalid input: Can not be empty string!");
}
}
private static int GetUserInt(String prompt)
{
String input = "";
while(true) {
System.out.print(prompt);
input = scanner.nextLine();
if (input.length() > 0) {
if (isValidInt(input)) {
int value = Integer.parseInt(input);
if (value >= 0) {
return value;
}
else {
System.out.println("Invalid input: Score can not be negative");
}
}
else {
System.out.println("Invalid input: Score must be a valid integer");
}
}
else {
System.out.println("Invalid input: Score can not be empty");
}
}
}
private static boolean isValidInt(String inString)
{
try {
Integer.parseInt(inString);
return true;
}
catch (NumberFormatException e) {
return false;
}
}
}
Hope this helps!

There are some things you can do, like checking the values with an if statement. You can say something like:
if(stringIsEmpty)
{
print ("Error");
}
else
{
/*Keep executing program*/
}
You could also use a try/catch block. This could help because if a string is null (empty), you can throw a null pointer exception and define it the way you want, like this:
try
{
/*blank string code*/
}catch(NullPointerException e)
{
System.out.println("Empty strings are not allowed");
}

Name output shows "null" Java

I am making a game-ish type of thing with three classes, combined. NOT HOMEWORK; hobby.
Codes for three classes:
Runner:
public class CounterGameRunner
{
// instance variables - replace the example below with your own
public static void main(String [] args){
Scanner input = new Scanner(System.in);
CounterGameCounter game = new CounterGameCounter();
System.out.println("You want to play a game I see. What is your name?");
String name = input.next();
game.NameIn(name);
CounterGAME game1 = new CounterGAME();
game1.actual();
}
}
Actual Game:
public class CounterGAME
{
// instance variables - replace the example below with your own
Scanner input = new Scanner(System.in);
int number;
int count=1;
boolean loop = true;
public CounterGAME(){
}
public void actual(){
CounterGameCounter game2 = new CounterGameCounter();
System.out.println("Guess a number between 1 and 101, see how many times you get it!");
number=input.nextInt();
int r = (int)(Math.random() * (100) + 1);
while(loop==true){
if(number < r){
System.out.println("Too small, try again");
number = input.nextInt();
count++;
game2.Counter(count);
} else if(number == r){
System.out.println("Wow, you won! Who'd have thought?");
count++;
game2.Counter(count);
break;
System.out.println(game2.done());
} else if(number > r){
System.out.println("Too large, try again");
number = input.nextInt();
count++;
game2.Counter(count);
}
}
}
}
Counter Class:
public class CounterGameCounter
{
// instance variables - replace the example below with your own
private String Name;
String done1;
int correct;
public CounterGameCounter(){
}
public String NameIn (String nm){
Name = nm;
return Name;
}
public String NameOut(){
return Name;
}
public void Counter(int count){
correct = count;
}
public int getCount(){
return correct;
}
public String done(){
done1 = "Name: " + NameOut() + "\n" +
"Times Answered: " + getCount();
return done1;
}
}
Problem:
The counter works properly and everything else displays and functions properly in the end. However, any name I input in the beginning always shows "null" while running the program. Why?

Your variable names are really confusing, and there are a lot of bad practices in your code, but null in name is because you create a new Counter in CounterGAME:
public void actual(){
// here
CounterGameCounter game2 = new CounterGameCounter();
// more code
}
Change actual to receive a CounterGameCounter:
public void actual(CounterGameCounter game2){
// more code
}
And call it like:
public static void main(String [] args){
Scanner input = new Scanner(System.in);
CounterGameCounter game = new CounterGameCounter();
System.out.println("You want to play a game I see. What is your name?");
String name = input.next();
game.NameIn(name);
CounterGAME game1 = new CounterGAME();
game1.actual(game);
// more stuff
}
FREE TIPS:
use String getName() and void setName(String)
start variable, object and attribute names with lowercase
String name;
Object object;
Variable names must be representative and descriptive
CounterGameCounter counterGameCounter = new CounterGameCounter();
This is also applicable to Object names:
GameCounter gameCounter = new CounterGameCounter();

try this:
String name = input.nextLine();
instead of:
String name = input.next();

InputMismatchError after implementing boolean

I've implemented a boolean to a kennel system I'm developing in Java and I'm getting an InputMismatchError when loading the data from the file.
I've read through a few times and tried to work it out but the solutions I'm trying aren't working. So far I've:
restructured the read in method (initialise) to read the data in properly and in the correct order, then assign it the newPet (local variable) in the correct order.
I then read through the .txt file (below) and made sure everything corresponded the the correct data, strings are being read as strings, ints as ints etc and that hasn't helped.
Can anybody spot the problem that's through the InputMismatch here?
Here is the error:
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Unknown Source)
at java.util.Scanner.next(Unknown Source)
at java.util.Scanner.nextBoolean(Unknown Source)
at KennelDemo.initialise(KennelDemo.java:79)
at KennelDemo.main(KennelDemo.java:337)
with line 79 and 337 being:
boolean mutualBoolean = infile.nextBoolean(); //and
demo.initialise();
Main class (apologises for the length)
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Scanner;
public class KennelDemo {
private String filename; // holds the name of the file
private Kennel kennel; // holds the kennel
private Scanner scan; // so we can read from keyboard
private String tempFileName;
private String dogsFile = "dogs.txt";
private String catsFile = "cats.txt";
/*
* Notice how we can make this private, since we only call from main which
* is in this class. We don't want this class to be used by any other class.
*/
private KennelDemo() {
scan = new Scanner(System.in);
boolean fileCorrect = false;
do {
System.out.print("Which animal are you looking to check into the kennel?: " + "\n");
System.out.println("Dog");
System.out.println("Cat");
tempFileName = scan.next();
if(tempFileName.toLowerCase().equals("dog") || tempFileName.toLowerCase().equals("cat")) {
filename = tempFileName.toLowerCase().equals("dog") ? dogsFile : catsFile;
fileCorrect = true;
}
else {
System.out.println("That is not a valid filename, please enter either 'Dog' or 'cat' in lowercase.");
}
}
while(!fileCorrect);
}
/*
* initialise() method runs from the main and reads from a file
*/
private void initialise() {
kennel = new Kennel();
System.out.println("Using file " + filename);
// Using try-with-resource (see my slides from session 15)
try(FileReader fr = new FileReader(filename);
BufferedReader br = new BufferedReader(fr);
Scanner infile = new Scanner(br)){
String kennelName = infile.nextLine();
int kennelSize = infile.nextInt();
infile.nextLine();
kennel.setCapacity(kennelSize);
int numPets = infile.nextInt();
infile.nextLine();
kennel.setName(kennelName);
for(int i=0; i < numPets; i++){
String PetName = infile.nextLine();
int numOwners = infile.nextInt();
infile.nextLine();
ArrayList<Owner> owners = new ArrayList<>();
for(int oCount=0; oCount < numOwners; oCount++){
String name = infile.nextLine();
String phone = infile.nextLine();
Owner owner = new Owner(name, phone);
owners.add(owner);
}
boolean mutualBoolean = infile.nextBoolean();
infile.nextLine();
String favFood = infile.nextLine();
infile.nextLine();
int feedsPerDay = infile.nextInt();
Pet Pet = new Pet(PetName, owners, mutualBoolean, favFood, feedsPerDay);
kennel.addPet(Pet);
}
} catch (FileNotFoundException e) {
System.err.println("The file: " + " does not exist. Assuming first use and an empty file." +
" If this is not the first use then have you accidentally deleted the file?");
} catch (IOException e) {
System.err.println("An unexpected error occurred when trying to open the file " + filename);
System.err.println(e.getMessage());
}
}
/*
* runMenu() method runs from the main and allows entry of data etc
*/
private void runMenu() {
String response;
do {
printMenu();
System.out.println("What would you like to do:");
scan = new Scanner(System.in);
response = scan.nextLine().toUpperCase();
switch (response) {
case "1":
admitPet();
break;
case "2":
changeKennelName();
break;
case "3":
printPetsWithBones();
break;
case "4":
searchForPet();
break;
case "5":
removePet();
break;
case "6":
setKennelCapacity();
break;
case "7":
printAll();
break;
case "Q":
break;
default:
System.out.println("Try again");
}
} while (!(response.equals("Q")));
}
private void setKennelCapacity() {
// set the boolean to check if the user REALLY wants to change the kennel size. We can never be too careful.
// boolean doContinue = false;
// Turns out the boolean does nothing, go figure.
// Still the error check works perfectly, now just a case of losing the temporary data if the program isn't closed through the menu.
// Kennel currently doesn't save until you use "q" at the menu to save the information. Possible solutions?
// Hello? Is this thing on?
int currentKennelCapacity = kennel.getCapacity();
System.out.println("The current kennel holds " + currentKennelCapacity + ", are you sure you want to change the current kennel size?");
String userWantsToContinue;
userWantsToContinue = scan.nextLine().toUpperCase();
if(userWantsToContinue.equals("Y")){
// doContinue = true;
System.out.print("Please enter the new size of the kennel you'd like: ");
int max = scan.nextInt();
scan.nextLine();
kennel.setCapacity(max);
System.out.println("The new kennel size is " + max + ", we'll now return you to the main menu. Please make sure the quit the program at the end of your session to save any changes. \n");
}
else System.out.println("No problem, we'll return you back to the main menu. \n");
//Duplicate code that caused an error when running through the conditions above, saved in case of future reference.
/* System.out.print("Enter max number of Pets: ");
int max = scan.nextInt();
scan.nextLine();
kennel.setCapacity(max);
*/
}
private void printPetsWithBones() {
Pet[] PetsWithBones = kennel.obtainDogsWhoLikeBones();
System.out.println("Pets with bones: ");
for (Pet d: PetsWithBones){
System.out.println("Pet name: " + d.getName());
}
}
/*
* printAll() method runs from the main and prints status
*/
private void printAll() {
Pet[] allPets = kennel.displayAllPets();
for (Pet p: allPets){
System.out.println("Animal name: " + p.getName());
System.out.println("Original owner(s): " + p.getOriginalOwners());
if(filename.equals(dogsFile)){
System.out.println("Do they like bones? " + Dog.getLikesBones());
}
else if(filename.equals(catsFile)){
System.out.println("Can they share a run? " + Cat.getShareRun());
}
System.out.println("Favourite food: " + p.getFavouriteFood());
System.out.println("Feeds per day: " + p.getFeedsPerDay());
System.out.println("====================================");
}
}
/*
* save() method runs from the main and writes back to file
*/
private void save() {
try(FileWriter fw = new FileWriter(filename);
BufferedWriter bw = new BufferedWriter(fw);
PrintWriter outfile = new PrintWriter(bw);){
outfile.println(kennel.getName());
outfile.println(kennel.getCapacity());
outfile.println(kennel.getNumOfPets());
Pet[] Pets = kennel.obtainAllPets();
for (Pet d: Pets){
outfile.println(d.getName());
Owner[] owners = d.getOriginalOwners();
outfile.println(owners.length);
for(Owner o: owners){
outfile.println(o.getName());
outfile.println(o.getPhone());
}
// TODO outfile.println(d.getLikesBones());
outfile.println(d.getFeedsPerDay());
outfile.println(d.getFavouriteFood());
}
} catch (IOException e) {
System.err.println("Problem when trying to write to file: " + filename);
}
}
private void removePet() {
System.out.println("which Pet do you want to remove");
String Pettoberemoved;
Pettoberemoved = scan.nextLine();
kennel.removePet(Pettoberemoved);
}
private void searchForPet() {
String allNames = kennel.getName();
System.out.println("Current pet in the kennel: " + allNames + "\n");
System.out.println("Which pet would you like to get the details for?");
String name = scan.nextLine();
Pet Pet = kennel.search(name);
if (Pet != null){
System.out.println(Pet.toString());
} else {
System.out.println("Could not find Pet: " + name);
}
}
private void changeKennelName() {
String name = scan.nextLine();
kennel.setName(name);
}
private void admitPet() {
boolean mutualBoolean = false;
if(filename.equals(dogsFile)){
System.out.println("enter on separate lines: name, owner-name, owner-phone, do they like bones?, favourite food, number of times fed");
}
else if(filename.equals(catsFile)){
System.out.println("enter on separate lines: name, owner-name, owner-phone, can they share a run?, favourite food, number of times fed");
}
String name = scan.nextLine();
ArrayList<Owner> owners = getOwners();
if(filename.equals(dogsFile)){
System.out.println("Does he like bones? (Y/N)");
}
else if(filename.equalsIgnoreCase(catsFile)){
System.out.println("Can the cat share a run? (Y/N)");
}
String booleanCheck;
booleanCheck = scan.nextLine().toUpperCase();
if (booleanCheck.equals("Y")) {
mutualBoolean = true;
}
System.out.println("What is his/her favourite food?");
String fav;
fav = scan.nextLine();
System.out.println("How many times is he/she fed a day? (as a number)");
int numTimes;
numTimes = scan.nextInt(); // This can be improved (InputMismatchException?)
numTimes = scan.nextInt();
Pet newPet = new Pet(name, owners, mutualBoolean, fav, numTimes);
kennel.addPet(newPet);
System.out.println("Pet " + newPet.getName() + " saved.");
// Save when you add new Pet in case the program isn't closed via the correct menu.
// Everything will still save when case "q" is used though.
save();
}
private ArrayList<Owner> getOwners() {
ArrayList<Owner> owners = new ArrayList<Owner>();
String answer;
do {
System.out
.println("Enter on separate lines: owner-name owner-phone");
String ownName = scan.nextLine();
String ownPhone = scan.nextLine();
Owner own = new Owner(ownName, ownPhone);
owners.add(own);
System.out.println("Another owner (Y/N)?");
answer = scan.nextLine().toUpperCase();
} while (!answer.equals("N"));
return owners;
}
private void printMenu() {
if(filename.equals(catsFile)) {
System.out.println("1 - add a new cat ");
System.out.println("2 - set up Kennel name");
System.out.println("4 - search for a cat");
System.out.println("5 - remove a cat");
System.out.println("6 - set kennel capacity");
System.out.println("7 - print all cats");
System.out.println("q - Quit");
}
else if(filename.equals(dogsFile)) {
System.out.println("1 - add a new dog ");
System.out.println("2 - set up Kennel name");
System.out.println("3 - print all dogs who like bones");
System.out.println("4 - search for a dog");
System.out.println("5 - remove a dog");
System.out.println("6 - set kennel capacity");
System.out.println("7 - print all dogs");
System.out.println("q - Quit");
}
}
// /////////////////////////////////////////////////
public static void main(String args[]) {
System.out.println("**********HELLO***********");
KennelDemo demo = new KennelDemo();
demo.initialise();
demo.runMenu();
demo.printAll();
demo.save();
System.out.println("***********GOODBYE**********");
}
}
and here is the .txt file being read from:
DogsRUs // kennel name
20 // capacity
3 // number of pets
Rover //pet name
2 // number of owners
Chris Loftus // first owner
1234 // phone number
Pete Hoskins // second owner
2222 // phone number
1 // boolean for mutualBoolean
biscuits // favourite food
// NOTE: for some reason favFood wasn't being added but it wasn't causing an error at all, it's the boolean that's throwing the input error. Structure above repeats for the data below.
Dinky
1
James Bond
007007
1
Gold fingers
catTest
1
Billy
456789
1
Curry
Clearly the problem is the boolean being read in but I really can't see the solution to it at all unfortunately. When mutualBoolean was likeBones (originally the program was only being used to check dogs in rather than dogs and cats) it was working fine.
Here is the code I've used to inherit for the mutualBoolean that's being used
import java.util.ArrayList;
public class Pet {
protected ArrayList<Owner> originalOwners;
protected boolean mutualBoolean;
protected String petName;
protected String favFood;
protected int foodPerDay;
public Pet(String name, ArrayList<Owner> owners, boolean mutualBoolean, String food, int mealsPerDay) {
petName = name;
this.favFood = food;
this.foodPerDay = mealsPerDay;
originalOwners = new ArrayList<Owner>();
for(Owner o: owners){
Owner copy = new Owner(o.getName(), o.getPhone());
originalOwners.add(copy);
}
this.mutualBoolean = mutualBoolean;
}
public String getName() {
return petName;
}
public void setName(String newName) {
petName = newName;
}
/*protected boolean mutualBoolean() {
return mutualBoolean;
}*/
/**
* Returns a copy of the original owners
* #return A copy of the original owners as an array
*/
public Owner[] getOriginalOwners(){
Owner[] result = new Owner[originalOwners.size()];
result = originalOwners.toArray(result);
return result;
}
/**
* How many times a day to feed the dog
* #param feeds The number of feeds per day
*/
public void setFeedsPerDay(int feeds){
foodPerDay = feeds;
}
/**
* The number of feeds per day the dog is fed
* #return The number of feeds per day
*/
public int getFeedsPerDay(){
return foodPerDay;
}
/**
* What's his favourite food?
* #param food The food he likes
*/
public void setFavouriteFood(String food){
favFood = food;
}
/**
* The food the dog likes to eat
* #return The food
*/
public String getFavouriteFood(){
return favFood;
}
/**
* Note that this only compares equality based on a
* dog's name.
* #param The other dog to compare against.
*/
#Override
public boolean equals(Object obj) { // Generated by Eclipse to be more robust
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Dog other = (Dog) obj;
if (petName == null) {
if (other.petName != null)
return false;
} else if (!petName.equals(other.petName))
return false;
return true;
}
/**
* A basic implementation to just return all the data in string form
*/
public String toString() {
return "Dog name:" + petName + "Original Owner:" + originalOwners + "Favfood:" + favFood
+ "FoodPerDay:" + foodPerDay;
}
}
and the Dog class
import java.util.ArrayList;
public class Dog extends Pet {
public static boolean likesBones;
public Dog(String name, ArrayList<Owner> owners, String food, int mealsPerDay, boolean likeBones) {
super(name, owners, likeBones, food, mealsPerDay);
Dog.likesBones = likeBones;
}
/**
* Does the dog like bones?
* #return true if he does
*/
public static boolean getLikesBones() {
return likesBones;
}
}

Java assignment don't know what is the mistake

the question is :
A fruit shop sells several types of fruits each day. Write a program that reads from user several lines of input.Each line includes a fruit's name,price per kilogram (as an integer), number of kilograms sold (as an integer).
the program should calculate and print the earned money of all fruits sold and fruit that achieved largest profit.
hint: -you could assume that user will insert valid data -user could stop the program via entering the word "stop" as a fruit's name.
Sample input and out put:
in each line, insert a fruit's name, price per kilogram, number of kilograms sold. To halt the program,insert "stop" as a fruit's name
banana 2 11
mango 3 8
peach 4 5
stop
the earned money of all fruits sold: 66
fruit that achieved the largest profit: mango
what i wrote now:
public static void main(String[] args) {
// TODO code application logic here
Scanner input = new Scanner (System.in);
String fruitname= " ";
String maxfruit = " ";
int price = 0,number=0;
int sum=0;
int max=0;
System.out.print("Fruit name, " + "price in killogram, number of killogram sold: ");
while (!fruitname.equals("stop"))
{
fruitname = input.next();
price = input.nextInt();
number = input.nextInt();
}
if (fruitname.equals("stop"))
{
sum = sum+(price*number);
}
if (max<(price*number))
{
max = price*number;
maxfruit = fruitname;
}
System.out.println("the earned money of all fruits is " + sum);
System.out.println("fruit that achieved the largest profit is "+ maxfruit);
}
}
the program is not reading what i submit to it, don't know why and not giving me the sum and the max fruit.. what is the problem of what i wrote?

As you can see your reads happen in the while loop:
while (!fruitname.equals("stop"))
{
fruitname = input.next();
price = input.nextInt();
number = input.nextInt();
}
Every time it loops - it overrides the values. Finally when you read stop and exit the loop - your fruitname is stop. So you need to fix your logic on how you would want to read in the input

Working variant:
public class FruitTest {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Fruit name, " + "price in killogram, number of killogram sold: ");
String text = input.nextLine();
String[] words = text.split(" ");
List<Fruit> fruits = parseInput(words);
int sum = getSum(fruits);
String popular = getPopularFruitName(fruits);
System.out.println("Got fruits: " + fruits.toString());
System.out.println("the earned money of all fruits is " + sum);
System.out.println("fruit that achieved the largest profit is " + popular);
}
private static String getPopularFruitName(List<Fruit> fruits) {
int max = 0;
String name = null;
for (Fruit fruit : fruits) {
int checkVal = fruit.getPrice() * fruit.getAmount();
if(checkVal > max) {
max = checkVal;
name = fruit.getName();
}
}
return name;
}
private static int getSum(List<Fruit> fruits) {
int result = 0;
for (Fruit fruit : fruits) {
result += fruit.getPrice() * fruit.getAmount();
}
return result;
}
private static List<Fruit> parseInput(String[] words) {
List<Fruit> result = new ArrayList<Fruit>();
int element = 1;
final int name = 1;
final int price = 2;
final int amount = 3;
Fruit fruit = null;
for (String word : words) {
if (word.equals("stop") || word.isEmpty()) {
break;
}
if(element > amount)
element = name;
switch (element) {
case name:
fruit = new Fruit(word);
result.add(fruit);
break;
case price:
if (fruit != null) {
fruit.setPrice(Integer.valueOf(word));
}
break;
case amount:
if(fruit != null) {
fruit.setAmount(Integer.valueOf(word));
}
break;
}
element++;
}
return result;
}
static class Fruit {
String name;
int price = 0;
int amount = 0;
Fruit(String name) {
this.name = name;
}
String getName() {
return name;
}
int getPrice() {
return price;
}
void setPrice(int price) {
this.price = price;
}
int getAmount() {
return amount;
}
void setAmount(int amount) {
this.amount = amount;
}
#Override
public String toString() {
return name + ". $" + price +
", amount=" + amount;
}
}
}
Comments to code - it's proper way to parse all the inputted string and parse it to an object that stores all the data - name, price and amount. Store all parsed objects into array or a list and then calculate max and popular fruit while looping your parsed fruit array

I found some mistake. The most important was in the while condition. Check this out.
public static void main(String[] args) {
// TODO code application logic here
Scanner input = new Scanner (System.in);
String fruitname = null;
String maxfruit = null;
int fruitSum = 0;
int totalSum = 0;
int max = 0;
System.out.print("Fruit name, " + "price in killogram, number of killogram sold: ");
while(!(fruitname = input.next()).equals("stop")){
fruitSum = input.nextInt() * input.nextInt();
totalSum += fruitSum;
if(fruitSum > max){
maxfruit = fruitname;
max = fruitSum;
}
}
System.out.println("the earned money of all fruits is " + totalSum);
System.out.println("fruit that achieved the largest profit is "+ maxfruit);
}
}

Oh it is reading it.
the problem is that it doesn't do what you want it to do.
the problems with the code I can see are this:
you are not storing the fruits quantities or prices anywhere, you need to store the values
in an array or something (maxFruit,MaxValue) to compare them later.
when you are reading the fruit values and a "stop" string is input the next step in your code is to wait for the price so it won't get out of the loop even if you input "stop", you need to restructure your scanner loop.
And if it is a beginner class it may be ok, but the code you are writing is not object oriented don't write the logic in the main.
You may want to learn to debug it is a very useful tool when you are learning to code, if you run this program in debug mode , you could see that the values are getting input and everything that is happening, Netbeans and Eclipse have very good debuggers and it would be worth to expend half an hour learning the basics of debugging It certainly helped me a lot when I was starting.

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class FruitSells {
public static void main(String... args) {
BufferedReader bufer = new BufferedReader(new InputStreamReader(System.in));
try {
String str;
String[] inarr;
int sumMoney = 0;
do {
str = (String) bufer.readLine();
inarr = str.split(" ");
for(int i = 1; i < inarr.length; i += 3) {
sumMoney += Integer.parseInt(inarr[i]) * Integer.parseInt(inarr[i + 1]);
}
System.out.println(sumMoney);
sumMoney = 0;
} while (!str.equals("stop"));
} catch(IOException ex) {
System.out.println("Problems with bufer.readLine()");
}
}
}
something like this you can modernize it.sorry for eng i can not speak))and write correctly of course))